JP2007083846A - Pedestrian protecting device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pedestrian protecting device for a vehicle capable of judging abnormality relating to collision detection means. <P>SOLUTION: This device comprises a collision sensor 1 and an acceleration sensor 2 installed to a vehicle and detecting collision; pedestrian protection means 4 such as an air bag for protecting the pedestrian colliding with the vehicle; a first control unit 31 of an ECU 3 receiving output signals of the collision sensor 1 and the acceleration sensor 2 and actuating the pedestrian protection means 4; alarm means 7 alarming abnormality relating to the collision sensor 1 and the acceleration sensor 2; an engine 5 giving predetermined vibrations to a vehicle body; a vibration sensor 6 mounted to the collision sensor 1 in a front bumper 8 and detecting cranking vibrations at the time of starting the engine given to the vehicle body by the engine; and a second control unit 32 of the ECU 3 comparing characteristics of detected vibration waveshapes of cranking vibrations detected by the vibration sensor 6 with characteristics of a reference vibration waveshape, and actuating the alarm means 7 when both of the characteristics are substantially different from each other. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a pedestrian protection device for a vehicle, and more particularly to a pedestrian protection device for a vehicle that can determine whether or not there is an abnormality related to a collision detection unit that detects a collision with a pedestrian or the like.

  Conventionally, when a vehicle collides with a pedestrian, there has been proposed a vehicle protection means for protecting a pedestrian by inflating and deploying an airbag on the hood of the vehicle or flipping up the back of the hood. Yes. For example, when the collision sensor provided in the vicinity of the front bumper detects a collision object, these vehicle protection means operate when the ECU receiving the signal from the collision sensor determines that the collision object is a pedestrian. (For example, refer to Patent Document 1).

JP 2004-268627 A

  A collision sensor that detects a collision with a guardian or the like is usually firmly fixed to a component of the vehicle body such as a front bumper or a bracket member. However, due to aged deterioration of components and the like, long-term running vibration of the vehicle, etc., there is a possibility that the attachment part of the collision sensor may be loosened and attachment failure may occur. Even in a minor contact accident where the pedestrian protection means does not operate, the structural members such as the bumper face around the collision sensor may be deformed.

  If the vibration transfer characteristic around the collision sensor changes due to the influence of such attachment failure or deformation, a signal waveform as expected may not be output from the collision sensor at the time of collision. In that case, the collision with the pedestrian cannot be normally determined based on the output of the collision sensor, and even if the vehicle collides with the pedestrian, the pedestrian protection means does not operate or does not collide with the pedestrian. Nevertheless, there is a risk that the pedestrian protection means may operate erroneously.

  Then, this invention aims at providing the pedestrian protection apparatus for vehicles which can judge the presence or absence of abnormality regarding a collision detection means.

  In order to achieve the above object, a pedestrian protection device for a vehicle according to the present invention is provided in a vehicle, and includes a collision detection means for detecting a collision, a pedestrian protection means for protecting a pedestrian that has collided with the vehicle, and a collision detection. A first control means for operating the pedestrian protection means in response to the output signal of the means, an alarm means for alarming an abnormality related to the collision detection means, a vibration generating means for applying a predetermined vibration to the vehicle body, and the vibration generating means The vibration detecting means for detecting the predetermined vibration applied to the motor and the characteristics of the detected vibration waveform of the predetermined vibration detected by the vibration detecting means and the characteristics of the reference vibration waveform are compared. A second control means for activating an alarm means when it is substantially different from the characteristics of the waveform is provided.

  According to the vehicle pedestrian protection device of the present invention configured as described above, the detection vibration waveform of the predetermined vibration given to the vehicle is compared with the reference vibration waveform to determine whether there is an abnormality related to the collision detection means. Can do. As a result, the user can be promptly maintained and the safety can be improved.

  Preferably, in the present invention, the vibration generating means is an engine mounted on a vehicle, and the vibration detecting means detects vibration from the engine immediately after starting the engine as a predetermined vibration. If the engine is a vibration generating means, it is not necessary to provide a new vibration generation source. Further, since the engine immediately after starting the engine has a large vibration, it is suitable for determining whether or not the collision detection means is abnormal.

  In the present invention, preferably, the collision detection means is provided in a front bumper of the vehicle. Since the front bumper is one of the parts that are most susceptible to damage in the vehicle at the time of a collision, the front bumper is suitable as a place for installing the collision detection means in detecting the collision.

  In the present invention, preferably, the vibration detection means is provided in a bumper reinforcement in the vicinity of the collision detection means. Thereby, when there is an abnormality such as a mounting failure in the collision detection means, the vibration detection means can easily detect a signal waveform having a waveform characteristic different from that at the normal time.

  In the present invention, preferably, the vibration detecting means is attached to the collision detecting means. Thereby, when there is an abnormality such as a mounting failure in the collision detection means, the vibration detection means can easily detect a signal waveform having a waveform characteristic different from that at the normal time.

  In the present invention, preferably, the pedestrian protection means includes an airbag device that can be deployed so as to cover at least one of the hood and the front window of the vehicle. Since the presence / absence of an abnormality related to the collision detection means is determined, it is possible to repair the abnormality at an early stage, and as a result, it is possible to prevent malfunction of the airbag device as a pedestrian protection means. .

In the present invention, preferably, the pedestrian protection means includes a lift device that can displace the rear part of the hood of the vehicle upward.
Since it is determined whether or not there is an abnormality related to the collision detection means, it is possible to perform repair at an early stage when there is an abnormality, and as a result, it is possible to prevent malfunction of the lift device as a pedestrian protection means.

  Thus, according to the vehicular walking vehicle protection measure of the present invention, it is possible to determine whether there is an abnormality related to the collision detection means.

Hereinafter, an embodiment of a pedestrian protection device for a vehicle according to the present invention will be described with reference to the accompanying drawings.
First, the basic configuration of the vehicle pedestrian protection apparatus according to the embodiment will be described with reference to FIG. FIG. 1 is a block diagram schematically illustrating a basic configuration of a vehicle pedestrian protection apparatus according to an embodiment.

As shown in FIG. 1, the pedestrian protection device for a vehicle according to the present embodiment includes a collision sensor 1 and an acceleration sensor 2 as collision detection means, an ECU 3 that realizes processing functions of first and second control means, and walking. It comprises a person protection means 4, an engine 5 as a vibration generating means, a vibration sensor 6 as a vibration detecting means, and an alarm means 7.
In the present embodiment, for convenience, the processing function corresponding to the first control means executed in the ECU 3 will be described as the first control unit 31, and the processing function corresponding to the second control means will be described as the second control unit 32. .

  The collision sensor 1 and the acceleration sensor 2 as collision detection means detect a collision with a pedestrian or the like, and are provided on the front bumper 8 of the vehicle. In the example shown in FIG. 2, the collision sensor 1 is constituted by an optical fiber portion extending in the vehicle width direction within the front bumper 8. When the optical fiber is deformed by the collision, the intensity of light propagating through the optical fiber portion changes. Therefore, a collision can be detected by detecting this change in light intensity.

Furthermore, in this embodiment, in addition to the optical fiber 1, the acceleration sensor 2 is used as an auxiliary. The acceleration change when colliding with a pedestrian is usually smaller than the acceleration change when colliding with a hard object such as a utility pole. For this reason, the output of the acceleration sensor 2 can be used to determine whether or not the collision object is a pedestrian.
In addition to the optical fiber and the acceleration sensor, any suitable device such as a piezo element can be used as the collision detection means.

  Moreover, the pedestrian protection means 4 protects the pedestrian who collided with the vehicle, and the thing of various aspects is applicable. For example, the example shown in FIG. 3 includes an airbag 22 that can be deployed so as to cover at least one of the hood hood 9 and the front window 10 of the vehicle, and an inflator 21 for inflating and deploying the airbag 22. Moreover, in the example shown in FIG. 4, it is comprised with the lift apparatus 23 which can displace the rear part of the hood hood 9 of a vehicle upwards.

  The first control unit 31 of the ECU 3 receives signals from the collision sensor 1 and the acceleration sensor 2 and outputs a control signal for operating the pedestrian protection means 4. The pedestrian protection means 4 explodes the explosive of the inflator 21 to inflate / deploy the airbag 22 or activate the lift device 23 according to the control signal.

  The vibration sensor 6 includes an acceleration sensor, detects cranking vibration immediately after the engine is started, and outputs a detected vibration waveform. The vibration sensor 6 is attached near the collision sensor 1 and the acceleration sensor 2 in the front bumper 8 in order to detect an abnormality in the vibration transmission characteristics around the collision detection means.

Here, the arrangement of the collision sensor 1, the acceleration sensor 2, and the vibration sensor 6 in the front bumper 8 will be described with reference to FIGS.
FIG. 5 is a horizontal sectional view of the front bumper 8 of the vehicle, and FIG. 6 is an exploded perspective view of the front bumper 8. In FIG. 6, the illustration of the bumper face 81 shown in FIG. 5 is omitted.

  As shown in FIGS. 5 and 6, the front bumper 8 mainly includes a bumper face 81 constituting the outer surface of the front bumper 8, and a bumper reinforcement extending in an arcuate shape in the vehicle width direction inside the bumper face 81. (Bumper beam) 82 and a shock absorber 83 provided between the bumper face 81 and the bumper reinforcement 82. The bumper reinforcement 82 is fixed to the front side frame 80 of the vehicle body constituting member at both ends.

  The collision sensor 1 is attached to a bumper reinforcement 82 via a bracket 84. The optical fiber portion 1b of the collision sensor 1 is fixed to the front surface of the bracket 84, and the optical transmission / reception portion 1a at one end of the optical fiber portion 1b is screwed to the bracket 84. In the optical fiber portion 1b, an U-turn is made at the other end of the optical fiber portion 1b, and both ends are connected to the optical transmitting / receiving portion 1a (1c in FIG. 7, not shown in FIGS. 5 and 6). .) Is resin-sealed.

  Furthermore, the acceleration sensor 2 and the vibration sensor 6 are attached to the collision sensor 1 via brackets 84 and 85. By attaching the vibration sensor 6 to the collision sensor 1, it becomes easy to detect an abnormality in the vibration transfer characteristics around the collision sensor 1.

  FIG. 7 shows another example of attachment of the vibration sensor 6. FIG. 7 is a longitudinal sectional view of the front bumper 8 taken along the midline before and after the vehicle. In the example shown in FIG. 7, the vibration sensor 6 is attached to the bumper reinforcement 82 via a bracket 86. This is particularly suitable for detecting an abnormality in the vibration transfer characteristics of the bumper reinforcement 82.

  The vibration sensor 6 may be attached to the acceleration sensor 2 directly or via a bracket or the like. In this way, it is particularly suitable for detecting an abnormality in vibration transfer characteristics related to the acceleration sensor 2. In the present embodiment, the vibration sensor 6 is provided separately from the collision detection means, but the collision detection means may also be used as the vibration detection means. For example, the acceleration sensor 2 may be used as the vibration sensor 6.

  The predetermined vibration detected by the vibration sensor 6 provided in this way is sent to the second control unit 32 of the ECU 3. In the present embodiment, cranking vibration immediately after the engine 5 is started is detected as the predetermined vibration. Cranking vibration is reproducible and has a large amplitude, and is therefore suitable for diagnosing abnormal vibration transfer characteristics.

The second control unit 32 of the ECU 3 compares the characteristic of the detected vibration waveform of the cranking vibration at the time of engine start output from the vibration sensor 5 with the characteristic of the reference vibration waveform.
Here, FIG. 8A shows a cranking vibration waveform immediately after the engine 5 is started. As indicated by the solid line I in FIG. 8A, the vibration with the maximum amplitude G1 is generated immediately after the engine start time T0. FIG. 8B shows a normal detected vibration waveform in the case where there is no abnormality such as attachment failure with respect to the collision detection means. In the vibration waveform indicated by the solid line II in FIG. 8B, the vibration reaches the time T1 after the time Td from the engine start time T0, and the maximum amplitude G2 is detected immediately after the time T1. This normal detected vibration waveform is used as a reference vibration waveform.

  In this embodiment, the presence or absence of abnormality is diagnosed using the delay time Td from the engine start time and the maximum amplitude G2 of the detected vibration waveform as the characteristics of the reference vibration waveform. Information on the characteristics of the reference vibration waveform may be stored in an internal or external storage unit of the ECU 3 and read and used as appropriate.

  Next, FIGS. 9A to 9C show examples of detected vibration waveforms in the case where there is an abnormality such as a mounting failure in the collision detection means. First, in the vibration waveform indicated by the solid line III in FIG. 9A, the vibration reaches the time T2 after the time Td1 from the engine start time T0, and the maximum amplitude G2 is detected immediately after the time T2. The maximum amplitude G2 in the detected vibration waveform is equal to the maximum amplitude G2 of the reference vibration waveform, but the delay time Td1 is longer than the delay time Td of the reference vibration waveform. Therefore, the vibration waveform detected by the vibration sensor 6 does not match the reference vibration waveform.

  Next, in the vibration waveform indicated by the solid line IV in FIG. 9B, the vibration reaches the time T3 after the time Td2 from the engine start time T0, and the maximum amplitude G2 is detected immediately after the time T2. The maximum amplitude G2 in the detected vibration waveform is equal to the maximum amplitude G2 of the reference vibration waveform, but the delay time Td2 is shorter than the delay time Td2 of the reference vibration waveform. Therefore, the vibration waveform detected by the vibration sensor 6 does not match the reference vibration waveform.

  Next, in the vibration waveform indicated by the solid line V in FIG. 9B, the vibration reaches the item T1 after the time Td from the engine start time T0, and the maximum amplitude G3 is detected immediately after the time T1. The delay time Td in the detected vibration waveform is equal to the delay time Td of the reference vibration waveform, but the maximum amplitude G3 is larger than the maximum amplitude G2 of the reference vibration waveform. Therefore, the vibration waveform detected by the vibration sensor 6 does not match the reference vibration waveform.

  The allowable range for determining the coincidence between the characteristic of the detected vibration waveform and the characteristic of the reference vibration waveform is various characteristics such as the content of the characteristic, the structure of the vehicle, the characteristics of the collision detection means, or the accuracy of the vibration detection means. It is better to set appropriately considering the conditions and experimental values.

  Then, the second control unit 32 of the ECU 3 compares the characteristic of the detected vibration waveform and the characteristic of the reference vibration waveform, and outputs an alarm signal that activates the alarm means 7 when the two characteristics are substantially different from each other. To do. The alarm means 7 is an indicator in a meter, for example, and lights up or blinks in response to an alarm signal. When the alarm means 7 is activated, an occupant or the like can know that the collision sensor 1 or the acceleration sensor 2 has an abnormality such as attachment failure. As a result, early maintenance of the vehicle can be promoted, and safety can be improved.

  In addition, when the characteristics of the detected vibration waveform and the characteristics of the reference vibration waveform match, for example, a lamp or the like for notifying that there is no abnormality may be turned on.

  Next, with reference to FIG. 10, the operation example of the pedestrian protection apparatus of this embodiment is demonstrated. FIG. 10 is a flowchart for explaining a control example of the ECU 3 in the present embodiment.

  First, when the engine 5 is started (step S1), the start of the engine is transmitted to the ECU 3 by an electrical signal. The second control unit 32 of the ECU 3 reads the detected vibration waveform of the cranking vibration immediately after the engine start output from the vibration sensor 6 and extracts the characteristic (step S2). Here, the delay time and the maximum amplitude described above are extracted as the characteristics of the detected vibration waveform.

  Subsequently, the second control unit 32 reads information on the characteristics of the reference signal waveform from a storage unit (not shown) (step S3). Here, the information on the delay time and the maximum amplitude is read as the characteristic of the reference vibration waveform.

  Next, the second control unit 32 compares the characteristic of the detected vibration waveform with the characteristic of the reference vibration waveform (step S4). As a result of the comparison, if the two characteristics are substantially different, the second control unit 32 outputs an alarm signal for notifying abnormality (step S5).

In this embodiment, the presence or absence of abnormality of the collision sensor 1 itself is further diagnosed.
Therefore, the ratio (Prx / Ptx) of the reception level (Prx) to the transmission level (Ptx) in the optical transmission / reception unit 1a in the collision sensor 1 is calculated (step S6). The light input from the optical transceiver 1a to one end of the optical fiber 1c propagates through the optical fiber 1c and returns to the optical transceiver 1a from the other end of the optical fiber 1c. When there is an abnormality in the collision sensor 1, the light intensity that returns to the optical transceiver 1a is reduced.

Therefore, the calculated signal level ratio (Prx / Ptx) is compared with the threshold signal level ratio (Pok) (step S7). As a result of the comparison, if the calculated signal level ratio (Prx / Ptx) is smaller than the threshold signal level ratio (Pok), an alarm signal is output to notify the abnormality (step S5). On the other hand, when the calculated signal level ratio (Prx / Ptx) is equal to or greater than the threshold signal level ratio (Pok), it is informed that it is normal (step S8).
In this way, it is possible to diagnose whether or not the collision detection unit is present without inputting a special test signal to the collision detection unit.

In each embodiment mentioned above, although the example which constituted the present invention on specific conditions was explained, the present invention can perform various change and combination, and is not limited to this.
For example, in the above-described embodiment, the example in which the engine is used as the vibration generating unit has been described. However, in the present invention, the vibration generating unit is not limited to this and may be arbitrarily suitable. In addition, when inspecting the vehicle, a predetermined vibration may be applied to the vehicle from the outside at a repair shop or the like.

  In the above-described embodiment, an example in which the delay time and the maximum amplitude are used as the characteristics of the detected vibration waveform has been described. However, the characteristics of the vibration waveform are not limited thereto. For example, a Bode diagram may be created to extract phase shift and gain frequency distribution characteristics.

It is a block diagram showing typically the basic composition of the pedestrian protection device for vehicles of the embodiment concerning the present invention. It is a front perspective view of a vehicle equipped with a collision sensor. It is explanatory drawing of an airbag apparatus. It is explanatory drawing of a lift-up apparatus. It is a horizontal sectional view of a bumper. It is a disassembled perspective view of a bumper. It is a vertical sectional view of a bumper. (A) is a graph schematically showing a vibration waveform generated from the engine when the engine is started, and (b) is a graph schematically showing a reference vibration waveform. (A)-(c) is a graph which shows typically the detection vibration waveform of a vibration sensor in case there exists abnormality regarding a collision detection means. It is a flowchart explaining the diagnostic process of the presence or absence of abnormality regarding the collision detection means by the 2nd control part of ECU.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Collision sensor 1a Optical fiber part 1b Optical transmission / reception part 1c Optical fiber 2 Acceleration sensor 3 ECU
4 Pedestrian Protection Means 5 Engine 6 Vibration Sensor 7 Alarm Means 8 Front Bumper 9 Bonnet Hood 10 Front Window 31 First Control Unit 32 Second Control Unit 41 Inflator 42 Airbag 43 Lift Device 80 Front Side Frame 81 Bumper Face 82 Bumper Rain Force 83 Shock absorber 84, 85, 86 Bracket member

Claims (7)

A collision detection means provided on the vehicle for detecting a collision;
Pedestrian protection means for protecting a pedestrian that has collided with the vehicle;
First control means for receiving the output signal of the collision detection means and activating the pedestrian protection means;
Alarm means for alarming abnormality relating to the collision detection means;
Vibration generating means for applying a predetermined vibration to the vehicle body;
The vibration detecting means for detecting the predetermined vibration applied to the vehicle body by the vibration generating means, the characteristic of the detected vibration waveform detected by the vibration detecting means and the characteristic of the reference vibration waveform are compared, and the detected vibration A pedestrian protection apparatus for a vehicle, comprising: a second control unit that activates the alarm unit when the waveform characteristic is substantially different from the characteristic of the reference vibration waveform. The vibration generating means is an engine mounted on a vehicle,
2. The vehicle pedestrian protection apparatus according to claim 1, wherein the vibration detecting means detects vibration from the engine immediately after the engine is started as predetermined vibration.   The pedestrian protection device for a vehicle according to claim 1 or 2, wherein the collision detection means is provided on a front bumper of the vehicle.   The pedestrian protection device for a vehicle according to any one of claims 1 to 3, wherein the vibration detection means is provided in a bumper reinforcement in the vicinity of the collision detection means. The pedestrian protection device for a vehicle according to any one of claims 1 to 4, wherein the vibration detection means is attached to the collision detection means.   6. The vehicle according to claim 1, wherein the pedestrian protection means includes an airbag device that can be deployed to cover at least one of a hood and a front window of the vehicle. Pedestrian protection device.   The said pedestrian protection means has a lift apparatus which can displace the rear part of the hood of a vehicle hood upwards, The pedestrian protection apparatus for vehicles as described in any one of Claim 1 thru | or 5 characterized by the above-mentioned.

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